Yes hmm... that was (and is) one of the large hurdles.

But on a different note, I think most tabletop games let you attack flying units and such as well.

If there is a swooping animation for attacks, then the hacking and such isn't all that bad. It would just seem like the ones on the ground are waiting for him to swoop and then attack, but failed the timing part.

The same can maybe apply to the collision circle; would you be willing to fight underneath a large flying animal like a dragon or gryphon?

Anyway, this is just thinking out loud ;). If I just had the skills to model such a flying unit, maybe I'd try, just for the heck of it, and see how it looks. Unfortunately, my drawing skills were are so bad I'm still amazed I passed those classes in highschool.